Ruud U802VA050317MSA Error Code A116_F: One-hour Lockout: Flame Presence Alarm
What Does Code A116_F Mean?
Fault code A116_F on the Ruud U802VA indicates a one-hour soft lockout triggered by detection of undesired flame when the gas valve is commanded off. The U802VA documentation specifically notes that the one-hour period begins after flame is no longer detected — meaning the lockout timer starts only once the undesired flame extinguishes.
This is a serious safety condition. Flame presence when the gas valve should be off indicates that either the gas valve is not closing properly (stuck open or leaking) or, less commonly, the flame sensor circuit is producing a false positive reading. A stuck gas valve allows gas to flow continuously to the burners, creating combustion hazards and the risk of carbon monoxide.
The Ruud U802VA documentation confirms that lockout conditions can be cleared by cycling power off and then back on. However, clearing the lockout does not fix the underlying cause. If the gas valve is stuck, power cycling will cause the furnace to attempt another heat cycle while the valve remains unable to close properly — which is dangerous. The manual gas supply valve should be shut off until a technician has confirmed the gas valve operates correctly.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Stuck or leaking gas valve | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- Turn off the manual gas supply valve immediately and call a technician — do not wait for the lockout timer to expire
- A technician must confirm that the gas valve closes fully when commanded off before the furnace is allowed to operate again
- Do not clear the lockout by cycling power until a technician has evaluated the gas valve
✓ Verified against manufacturer service manual — March 2026